Chilies are the dried ripe red fruits of the genus capsicum. The two well-known species are Capsicum annum L. and Capsicum frutenscens L. India is the largest producer and exporter of chilies. The estimated export of dry chilies from India was 75,000 MT tonnes valued Rs. 25580 lakhs in 2001–02.
Pungency and color are the two main quality attributes in chilies. The red color of chilies is due to the presence of carotenoid pigments like capsanthin, (major pigment, 35%) capsorubin, zeaxanthin, violaxanthin, cryptoxanthin, β-carotene etc. These pigments are present in chilies mainly in the esterified form, and to a small extent in non-esterified forms. The oleoresin of chilies is used in many processed foods like sausages, seafood, meat products etc. to impart a reddish taint and pungency. It is also used in chicken feed so that chicken meat and yolk will get an attractive reddish shade. For food colouration, pungency free, high color content chili oleoresins are desirable. Chili oleoresins as commercially produced vary in their pigment content and the color value ranges from 30,000 to 1,00,000 units as, measured by the method prescribed by the Essential oil Association of America (EOA). The color content of the oleoresin is directly proportional to the pigment concentration the raw material used. But preparation of oleoresin with high color values is desirable. The present invention relates to a process to upgrade the color value of pungency-free commercial chili oleoresin.
There are several patents on chili/paprika color, relating to the following aspects:
    i. Methods for alcohol or oil extraction, usually after saponification with alkali (No. 31,522 Israel 1971, No. 76,142,020, Japan 1976, No. 80,118,967, Japan 1980, No. 81,011,960, Japan 1981, No. 82,133,160, Japan 1982, No. 82,180,663, Japan 1982, and 83,173,164, Japan 1984).    ii. Pigment production by inter-esterification, No. 79,142,236, Japan 1979).    iii. Methods for pigment stabilization or prevention of fading (54,010,568, Japan 1979 No. 55046, 147, Japan 1980, No. 76,112,561, Japan 1976) and    iv. Preparation of formulations for food use (81,011,961, Japan 1981).Other patents relating to paprika color are as follows:    i. Method of preventing paprika color from fading (JP52128924, 1977),    ii. Production of paprika color involving the use of calcium hydroxide and solvent extraction (JP57131259, 1982),    iii. Production of paprika dyestuff by treating paprika extract with caustic alkali in presence of acetone (JP61264061, 1986),    iv. Improvement of paprika color stability to oxygen and light by blending with carrot extract and browning reaction product of a saccharide and amino acid (JP57031962, 1982),    v. Fade preventing agent for paprika pigment by adding a browning reaction product of a saccharide and an amino acid (JP56041259, 1981),    vi. Fade inhibition of paprika color by adding solvent extract of rosemary, sage or mixture thereof (JP57102955, 1982),    vii. Manufacture of odourless paprika colouring matter by absorption of alcohol extract of paprika on a resin of porus polymeric structure (JP3045657, 1991),    viii. Production of stable deodorise paprika pigment by bringing paprika oleoresin into contact with carbon dioxide in supercritical state in presence a polar solvent (JP2038464, 1990),    ix. Production of concentrate paprika pigment by treating paprika with lipase followed by solvent extraction (JP62115067, 1987),    x. Method for separating paprika pigment by silica gel chromatography (JP62115068, 1987),    xi. Manufacture of paprika oleoresin capsule by treatment with molto dextrin and modified starch (KR9310538, 1993),    xii. Method for production of colouring agent and flavouring material from paprika (HU63311, 1993),    xiii. Process for isolation of flavour and color from paprika (HU185706, 1985),    xiv. Method for obtaining aromatics and dyestuffs from bell peppers involving extraction with a solvent in a supercritical state (HU28336, 1983),    xv. Improvement of color stability by treatment with vegetables and fruits, which contain carotenoids (U.S. Pat. No. 5,888,574, 1999),    xvi. Natural food color composition involving mixture of edible materials including paprika and palm oil, carrot oil or corn gluten oil (U.S. Pat. No. 4,304,792, 1981),    xvii. High temperature counter current solvent extraction (U.S. Pat. No. 5,773,095, 1998),    xviii. Method of stabilising a spice extractive and a preservative product by using a small amount of metal deactivator such as an edible water soluble salt of ethylene such as diamine tetra acetic acid (GB974322, 1964),    xix. Color stabilised paprika composition using a natural antioxidant/oil soluble ascorbic acid ester (US19900525340, 19900518, 1991),    xx. Preparation of emulsified paprika color (JP2001252043, 2001), prevention of paprika pigment fading using caffeic acid ferulic acid, chlorogenic acid and some of their esters etc. (JP57117566, 1992).The above patents do not teach or does not provide any clue regarding improved extraction of chili oeloresin and recovery of carotenoid.
According to a published paper by Santamaria et al., “Selective enzyme mediated extraction of capsaicinoids and carotenoids from chili guajillo puya (Capsicum annum L) using ethanol as solvent” in J. Agric.Food Chem. 2000, 48, 3063–3067, selective extraction of capsaicinoids and carotinoids from the Mexican chili Guajillo “puya” was studied. Ethanol was used as solvent for the extraction of carotenoids and capsaicin from chili powder treated with commercial enzymes (individually) containing a) pectolytic as well as hemicellulolytic: activities, (b) cellulotytic activity, (c) a wide variety of carbohydrase activities d) with pectin esterase and arabanase activities. It was recommended that, pre-treatment of the flour with a commercial enzyme namely VISCOZYME L (with a wide variety of carbohydrase activities having 120 units of fungal β-glucanase (FBG)/ml) at 5% level on chili powder helped to get an increased yield of 11% for carotenoid and 7% for capsaicinoids respectively, over control chili powder.
In the present patent proposal using two commercial enzymes namely (a) EXTRAZYME (with declared activity of 7500 pectinase S units and a multi-enzyme complex containing a vide range of carbohydrases, including arabanase, cellulase, β-glucanase, hemi-cullalase, and xylanase and (b) ENERGEX, in powder or liquid form, with declared activities of 50–120 fungal β-glucanase per gram or ml and 5000 to 12000 PSU per gram or ml.
The method reported in the publication referred to above, has many disadvantages, which are overcome in the present patent application.    1) As per the paper, the chili powder to water ratio is very high being of the order of 1:50 which needs to be dried before extraction. This step of removal of water in large quantities involves time and energy, which would make the processes uneconomical. In the present patent proposal material to water ratio for enzyme treatment is far less (1:1) which makes the drying step easier and faster    2) Enzyme addition to the chili powder as reported in the paper ranges from 1–5% and actually the authors recommend 5% of the enzyme. In the present patent proposal maximum level required is 1% only.    3) The increase in the yields of carotenoids and capsaicinoids as per the referred paper is 10% for carotenoids and 7% for capsaicinoids over the control batch. In contrast to this in the proposed patent, the increase in yields of carotenoids and capsicinoids is of the order of 24% and 32% respectively, which is very much higher.    4) The solvent used in the publication is aqueous alcohol or pure alcohol. In the proposed patent a mixture of solvents with an advantage of improved extractability for chili constituents namely, carotenoids and capsaicin has been employed    5) Commercial scale adaptation is feasible for the process claimed in the patent application
In the spice extraction industry, chili oleoresin is produced by extraction of chili powder with solvents such as acetone, ethylene dichloride and hexane followed by desolventization to get a deep red coloured, viscous material called the oleoresin. The oleoresin contains the constituents responsible for color namely carotenoids, the pungent constituents mainly capsaicin and dihydrocapsaicin, besides other soluble components such as fats and waxes.
The present patent aims at enhancing the extractability of chili constituents especially pigments and capsaicinoids by a combination of two techniques namely enzyme treatment and extraction with selected solvent mixtures.